The present invention relates to display system. More specifically, the present invention relates to a touch screen. More particularly, the present invention relates to a connector for electrically coupling layers of a touch screen.
A touch screen is generally known. Such touch screen is typically used in front of a computer-driven display that is capable of displaying variable images, or a non-variable display that is capable of providing fixed images. Such touch screen may xe2x80x9csensexe2x80x9d or recognize the existence and location of a xe2x80x9ctouchxe2x80x9d on its exterior surface so that a user can input commands to an accessory (e.g., a general purpose computer). A touch screen may be resistive or capacitive, analog or matrix.
In a resistive touch screen, during an input event or xe2x80x9ctouchxe2x80x9d an electrically conductive flexible layer is deformed, bent or pressed across a gap to contact an electrically conductive stable layer. When the flexible layer contacts the stable layer, the touch from an input element or device (e.g., finger or stylus) can be xe2x80x9csensed.xe2x80x9d When the flexible layer of a matrix touch screen is pressed, a discrete switch is closed and two electrically conductive coatings (e.g., a transparent coating patterned in rows on one surface of the flexible layer and patterned in columns orthogonal to the rows on the opposing surface of the stable layer) are brought into electrical contact. The discrete switch is associated with a particular row and column. A computer or other electronic circuit can be used to provide electric signals to the rows and columns and determine the horizontal and vertical position (X, Y coordinate) associated with the closed discrete switch.
However, a problem with such touch screen is that the material that physically and electrically attaches the flexible layer to the stable layer (i.e., cured epoxy having a conductor) is hard and rigid and may crack or obtain fissures due to temperature and humidity changes. Other disadvantages of such epoxy include: storage of the epoxy at a cold temperature of about xe2x88x9240xc2x0 C., since such epoxy typically has a pot life or useful life of about six hours at room temperature, which may result in unused or unusable epoxy material; warming of the epoxy before use; curing of the epoxy at a high temperature of about 87xc2x0 C., which may require curing equipment (e.g., an oven), time (e.g., about one-hundred and twenty minutes), and which may affect other materials of the touch screen (e.g., shrinkage/expansion of the stable and flex layers).
Accordingly, there is a need for a touch screen conductor to couple the flexible layer to the stable layer that may be stored at ambient temperature. There is also a need for a touch screen fastener that may be semi-rigid. There is also a need for a low cost connector that may be easily applied in a touch screen application. There is also a need for a touch screen connector that may be applied at room temperature. Thus, it would be advantageous to provide a touch screen having features that fulfill one or more of these needs. These and other features will become apparent to one of skill who reviews this disclosure and appended claims.
The present invention relates to a display system. The display system may include a display panel for display of information. The display system may also include a touch screen coupled to the display panel. The touch screen may include a base layer physically coupled to a cover layer. The touch screen may also include a semi-rigid conductor for electrically coupling the base layer to the cover layer. The conductor may be generally dispensable at about room temperature.
The present invention also relates to a touch screen including a semi-rigid conductor for electrically coupling a base to a cover.
The present invention also relates to a touch screen. The touch screen may include a first means for providing an electrically conductive material. The touch screen may also include a second means for providing an electrically conductive material. The touch screen may also include a connector for electrically coupling the first means to the second means. The connector may be generally dispensable at about room temperature.
The present invention also relates to a method of manufacturing a touch screen. The method may include providing a first layer having a first relatively translucent surface. The method may also include providing a second layer having a second relatively translucent surface. The method may also include dispensing a conductor on at least one of the first surface and the second surface thereby electrically coupling the first surface to the second surface. The conductor may have a viscosity of at least about 5,000 centipoise at 0.3 RPM at about room temperature. The conductor may also have flexibility sufficient to compensate at least partially for relative movement of the first layer and the second layer due to environmental changes.